Overview Also known as vitamin B9 or folate Used to form tetrahydrofolate (THF) important for DNA and RNA synthesis Found in leafy greens and fresh fruits Absorbed in the jejunum and ileum Small reserve pool is stored in the liver lasts 3-4 months Deficiency Folic acid deficiency causes a megaloblastic anemia Most common vitamin deficiency in the United States Causes dietary deficiency elderly goat milk alcoholism pregnancy deficiency can be caused by several drugs e.g., phenytoin, sulfonamides, methotrexate, EtOH, 5-fU, and oral contraceptives Presentation macrocytic, megaloblastic anemia hypersegmented neutrophils homocystinemia ↑ risk of DVT and atherosclerosis supplemental folic acid can reverse this risk no neurologic symptoms (as opposed to vitamin B12 deficiency) deficiency in pregancy causes fetal neural tube defects supplemental folic acid in all reproductive-age women who are attempting to become pregnant reduces risk